Using kitchen shears or clean scissors, cut two straight lines from the thick part of the underside of the tail to the thin part on either side of the tail. Peel the thin membrane back toward the tip of the tail. Using your finger, pull the meat away from the top part of the shell until you can pull the lobster tail down away from the top of the tail through the bottom where you made the cuts. The tail should pull out of the shell quite easily.
Season the lobster tails with salt and pepper. Put the tails in the sous vide bag, add the cold butter, thyme, bay leaf, and garlic to the bag and seal.
Once the water bath is to temperature, add the bag to the water and set a timer for 45 minutes.
Make the Lemon Beurre Blanc Sauce
With about 5-10 minutes left on the timer, start the beurre blanc. Heat a saucepan over medium heat with the peppercorns in the pan for about a minute to toast the peppercorns. Add the oil and chopped shallots and reduce the heat to medium low. Cook until the shallots are translucent, then add the lemon zest. Add the wine and cook until the wine has reduced by half.
Remove the sauce from the heat, strain through a fine mesh strainer into a container. Make sure the pan doesn’t have any solids but do not wash it. Return the pan to the stovetop and pour the strained sauce back into the pan. Continue to cook until there is about 3 tablespoons of liquid remaining.
Remove the pan from the heat and let it stand for 30 seconds. Whisk in the cold butter 1 tablespoon at a time until the sauce has a silky texture. Add salt to taste.
Remove the lobster from the sous vide bag, plate and top with the beurre blanc. Serve garnished with parsley and a lemon!